As a method for measuring a masticatory ability of teeth (natural teeth and artificial teeth), as described in JP-2005-237710-A, JP-2008-220600-A and “Guideline for masticatory disturbance evaluation method-primarily method for measuring a masticatory ability—”, Prosthodontic Journal, 2002, vol. 46 no. 4, p. 619-625, it is introduced a method for determining a masticatory ability by means that a human actually masticate something.
With such method, an effect of a muscular power, a chewing habit and the like of a human subject, and an effect of an occlusal geometry of teeth (including artificial teeth) can not be separately measured. Especially, at fabrication or adjustment of an artificial tooth, it is preferable that a masticatory ability resulted from an occlusal geometry of the artificial tooth can be independently evaluated.
In natural teeth, a maxillomandibular occlusal condition according to a crowding condition of teeth and a wear of teeth with aging significantly affect an ability of chewing a food. However, any device or method for measuring a masticatory ability due to a condition of arrangement and occlusion of teeth is not known.
Also, in artificial teeth, a maxillomandibular occlusal condition according to an arrangement condition of teeth, a grinding of the artificial teeth and a wear of teeth after use for a certain period affect an ability of chewing a food. However, any device or method for measuring a masticatory ability due to a condition of arrangement and occlusion of teeth is not known.
Specifically, a comparison between different dentures or between a denture before use and the same denture after use is not made, and therefore evaluation of a time for replacement of a denture or a masticatory ability of a denture can not be made. Also, a masticatory ability of a denture is influenced a great deal by an occlusal force, a chewing habit and a diet habit of a patient, and therefore appropriate dentures different according to patients. Consequently, it is desired a method for evaluating previously whether a masticatory ability of a denture for a certain patient is appropriate or not, at a fabrication of a denture.
If a masticatory ability of a denture can be recognized before the denture is put in a patient, it can be used as information for a treatment and a diagnosis of the patient and can also be put to use in next treatment.
Further, if the masticatory ability can be quantified, it can be determined whether the fabricated denture is appropriate or not by defining a threshold value, and it can be quantitatively evaluated how much masticatory ability the fabricated denture has.